Purpose :
The importance of reticular pseudodrusen (RPD) as a retinal phenotype associated with age-related macular degeneration (AMD) but long follow-up data is still lacking. We conducted a multicenter, longitudinal, observational, study to determine whether RPD confer a long-term increased risk of progression to late AMD in the second eye of patients with unilateral exudative-AMD (eAMD).

Methods :
Fellow eyes of patients with unilateral eAMD were recruited from 2 european centers and evaluated on the risk of progression to late-AMD. A minimum follow-up of 5 years was required, unless progression occurred first. Baseline retinal profile of patients was evaluated using a multimodal imaging approach that included color fundus photographs (CFP), fundus auto-fluorescence (FAF), infra-red (IR), optical coherence tomography (OCT), and red-free (RF) images. Baseline images were graded by two separate centers. Main outcome measures were the incidence of choroidal neovascularization (CNV) and geographic atrophy (GA).

Results :
We recruited 88 patients (48 female) with a mean age of 75.6 ± 7.1 years and a mean follow-up of 65.7 ± 20.9 months. Baseline prevalence of RPD was 58% (n=51). There was no statistically significant association of RPD with increased age (p=0.29) or sex distribution (p=0.39). The most sensitive image modality for RPD was IR (93%), followed by FAF (92%), OCT (74%, RF (33%) and CFP (29%). After 5 years, 54.50% (n=48) of the study eyes progressed to late-AMD. Of those, 81.25% (n=39) developed CNV and 18.75% (n=9) geographic atrophy (GA). After correcting for age and sex, the presence of RPD was significantly associated with development of late-stage AMD (OR=2.55, p=0.03). In a multivariate analysis using a model that included other known risk markers – hypo and hyperpigmentation, intermediate drusen, and large drusen - the association between RPD presence and increased risk of progression was still observed but no longer reached statistical significance (OR=2.35; p=0.089).

Conclusions :
RPD are highly prevalent in the fellow eyes of patients with unilateral AMD. Presence of RPD is associated with increased long-term risk of progression, highlighting the importance of comprehensive multimodal retinal imaging and careful monitoring of at-risk patients.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.